Messages in this thread | | | Subject | Re: [PATCH v4 07/15] iommu/vt-d: Delegate the dma domain to upper layer | From | Lu Baolu <> | Date | Mon, 24 Aug 2020 14:31:23 +0800 |
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Hi Chris,
On 2020/8/22 2:33, Chris Wilson wrote: > Quoting Lu Baolu (2019-05-25 06:41:28) >> This allows the iommu generic layer to allocate a dma domain and >> attach it to a device through the iommu api's. With all types of >> domains being delegated to upper layer, we can remove an internal >> flag which was used to distinguish domains mananged internally or >> externally. > > I'm seeing some really strange behaviour with this patch on a 32b > Skylake system (and still present on mainline). Before this patch > everything is peaceful and appears to work correctly. Applying this patch, > and we fail to initialise the GPU with a few DMAR errors reported, e.g. > > [ 20.279445] DMAR: DRHD: handling fault status reg 3 > [ 20.279508] DMAR: [DMA Read] Request device [00:02.0] fault addr 8900a000 [fault reason 05] PTE Write access is not set > > Setting an identity map for the igfx made the DMAR errors disappear, but > the GPU still failed to initialise. > > There's no difference in the DMAR configuration dmesg between working and > the upset patch. And the really strange part is that switching to a 64b > kernel with this patch, it's working. > > Any suggestions on what I should look for?
Can the patch titled "[PATCH] iommu/intel: Handle 36b addressing for x86-32" solve this problem?
Best regards, baolu
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